The combination of silicon-containing molecules with polybutylene is known in the art, for instance, Iwahara et al. in U.S. Pat. No. 4,904,732 teach the formation of an isobutylene polymer having at least one silicon-containing group which is crosslinkable by the formation of a siloxane bond. The polymer described therein is said to be curable at room temperature to produce materials with weatherability, weather resistance, heat resistance, electric isolation and gas impermeability. This patent does not, however, describe polysiloxane-polybutylene copolymers in which polybutylene chains are grafted onto polysiloxane backbones.
Similarly, Saam in U.S. Pat. No. 4,808,664 teaches the formation of polyisobutylene oligomers containing siloxane functional terminal groups. This patent teaches that such materials cure at room temperature in the presence of moisture. Again, however, the patent teaches a main chain of isobutylene monomer units with a siloxane functional terminal unit as opposed to polysiloxane backbone copolymers with polybutylene chains grafted thereon as claimed herein.
Kennedy et al. in U.S. Pat. No. 5,663,245 teach novel multi-arm polymers comprising polyisobutylene arms connected to a well-defined siloxane core. This patent teaches that the resultant materials are acid stable, have low viscosity with high molecular weight, and are useful as motor oil additives. This patent, however, does not describe the copolymers claimed herein.
In U.S. Pat. No. 5,741,859, there is described a method of preparing a polyisobutylene-siloxane block copolymer via non-equilibrium anionic polymerisation of a diorganocyclotrisiloxane using a silanolate functional polyisobutylene as the initiator. Resulting copolymers are described and include certain di-block, tri-block, branched or star copolymers.
We have now discovered novel polysiloxane-polybutylene copolymers which have both siloxane and organic copolymer characteristics and, as such, are particularly useful in the personal care industry.